<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			/*(1,1,2)*/
			#box1 div.cl2 p,#box1 #box2 p{
				color:blue;
			}
			/*(2,0,1)*/
			/*#box1 #box2 p{
				color:blue;
			}	*/
			/*(2,0,2)*/		
			#box1 div#box3 p{
				color:red;
			}	
			/*(2,0,1)*/	
			#box1 #box3 p{
				color:green;
			}
		</style>
	</head>
	<body>
		<div id="box1" class="cl1">
			<div id="box2" class="cl2">
				<div id="box3" class="cl3">
					<p>唧唧复唧唧，木兰生小鸡</p>
				</div>
			</div>
		</div>
	</body>
</html>
